How to merchant on runescape?

i usually buy an item for a little bit lower than it's market price then i usually sell it back for market price. if you can buy in mass chunks, you're good for making profit. i usually would stick to rare items that are fallig in price because they will go back up. if orders don't come in instantly, relax they'll come in soon. remember, high in demand or rarities that are dropping in price are usually best best of luck

You can check out these guides

http://www.g4hq.com/runescape-guides/
http://www.g4hq.com/runescape-guides/14024-f2p-money-making.html